Dennett: treat a system as if it has beliefs, and you can often predict it

Daniel Dennett argued any system — a person, a thermostat, a chess program — can be explained at three levels: physical, design, or "intentional," where you simply assume it has beliefs and desires and ask what a rational agent would do. He said this intentional stance isn't a claim about what's really inside a system, just the most useful strategy for predicting its behaviour when it works.

— Daniel Dennett, The Intentional Stance — MIT Press, 1987
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